The Predatory Efficacy of Amblyseius swirskii (Athias-Henriot) to Tyrophagus putrescentiae

To identify the functional response of Amblyseius swirskii(Athias-Henriot) to Tyrophagus putrescentiae,a study on the prey preference, prey response and intraspecific interference were made using the method of functional response of the predator to the prey at five temperatures(16, 20, 24, 28 and 32℃) and RH(85±5)℃ under the laboratory condition.The results showed that A. swirskii preferred nymphs of T.putrescentiae rather than female adults. Predatory functional response was in accordance with Holling Ⅱ equation. At 16-28℃, the average treatment time decreased with the increase of temperature, the predatory number decreased when temperature was over 32℃. The predatory rate decreased with the increase of the predator density under the same prey density. The competition and intraspecific density interference effect was found for the A. swirskii during its predation. All the results will provide a theoretical base for the control on T.putrescentiae infesting potato using A. swirskii.